New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1887-01-27
SECRETARY WHlTNEY'S COMPARISONS.

THE FIGURES GIVEN IN HIS ANNUAL REPORT MIS-
LEADING-LETrER FROM A MARINE ENGINEER.
TO the Editor OF The Tribune.
SIR: am glad to see that some newspapers are not
afraid challenge the correctness of Secretary Whit
news official reports of the performances of he
cruisers. cannot believe that the misleading state
meats relative to the comparisons of speeds between
the Dolphin and Atlanta and some of the English
cruisers emanarsd from any other SQUIRE, than that
of bis fayorites at the Navy Department for # the
Secretary understood anything of tie science of naval
construction he would not have issued such a falslf
cation of facts his recent report contained In TIE
TRIBUNE Tuesday attention was oalied to the opin
ions expressed by marine engineers that the method OF
comparison of the Atlanta with three Englisn-built
vessels was unfair aud inscriptions. Milder al
iectives coud not have been used. Here Is what the
Secretary says
The Atlanta ship to the Boston can be compared
KIT ,ns wsP bns IN Ems and Tue smsrds Chill
Giovanni Banssn for and the merse Tor tine ahs sa
1920 the Giovanni au;an So6s and the Mersey
ssS I1s S o. ssos the
I aea in cas that her engines viii develop $500
se oe and ns el.ey lS The
speed the Atlanta VII be less than 10 knots we sa aaI %
knots the Mersey 10 knots
Here is the Atlanta, ship with twothirds of full
sail power and with double bottom, compared with
the Esmerada and the Giovanni Bausan, IN wnich' 10
order obtain speed sail power and double bottoms
dispensed with TO obtain more weight aud Pac 10
accom- modate the machinery and coal. Inc Esmer-
aida and Giovanni Bausan are said to have been eacn
designed for 100 horsepower which was exceeded
Or trial to the extent of 800 horsepower by the
former ship and $50 by the latter This statement
is so startling as TO invite investigation. Assuming
that know nothing abomt what power these vessels
intended develop, one must fall back upon .he
expedieDt of comparing them with other ships OF whch
the designed power is known. Fortunately We have
the Nanwi-Kan, vessel by the same builders anu
the same type of engines, to give the data duplicate
of this vessel the Baltimore Is being built by the
Government and in the published specifications find
details Of her machinery as follows: diameter OF
highpressurc cylinders, A inches; diameter OF low
pressure cylinders 80 inches; stroke, feet crate
surface 800 square feet. There Is also an auxiliary
boiler which from The description given cannot contain
than 20 square tte of CRATE thus giving total
crate surface Of 412 square feet The corfesi ondng
dimensions of the machinery OF the Esmerads ana
Giovanni Bausan Diameter OF highpies-ure
Under 43 inches diameter OF ow-pressure cylinder
So inches stroke, feet; crate surface, 4SO square
feet.
IL is officially stated that the Nanwa-Kan was
designed for 800 horsepower under forced draft
Taking this Ms q basis let us see what the same
designers must have intended for the power of the
Esrnerada and her sister-ship. Comparing the power
by the capacity OF the boilers when Is represented by
the crate surface find that the boilers OF the Esmer
aida will furnish steam for Az 73S horse
power under forced drat Comparing by the capacity
OF the gD-pressdre cylinders, find that the Esmer-
alda's engines can work Od enough steam TO give
As.,,55;s9ol=7,111 horsepower. Comparing by the
capacity of the owpressure cylinders, dnd that they
., -, eio;ort si7e "a oive s2sk'.2oo=f osO horse
power.
Taking the smaller of the above figures, If the
Nauiwa-kan designed To make 100 horse power,
these other ships he said to have been designed
Tor at least $500 Horsepower instead OF 5,1OO as
stated by the Secretary. Then, instead OF having
overrun her intended horsepower by l,1s0 the
Giovanni Bausan has underrun IL by 300, and the
Esmeralda instead OF having 800 extra horsepower
to her credit, mus; DO dcbted with 800 Gehoieney
The tact oi the whole matter is that the $500 horse
power mentioned only that which was intended
10 ho me ~.
the Esmeralda and Bausan were designed was the Gus
of English bu lders to state the intended natural
draft horsepower instead OF the fotcel-drlft
horse power, as Is at present the practice. The
figures given as the intended horsepower of the
Atlanta represent The maximum power under orccd
draft Then, again, while the Atlanta has had two
or three trials with results OF continually easing
sa-tactlon the trials OF the Giovanni Bausan are said
to have numbered at least bakers dozen before tho
recorded performance wa reached, aud before the |
vessel was accepted by the tia ian Government |
Moreover the speed OF the Esmera.da was mnde, not
ike the Atlanta for six hours, but over course OF
only eleven mil, s, while the Giovanni Dausan WA
jockeycd over a course oi only TX miles. Then again
the coal used the English rias is the finest N the
world, freshly mined and hond-picked Nixon |
Navigation coal; but on the Atlanta Cumberland
mixed with Cardiff coal was nsed, and which had
been subjected to long exposure and many tunes |
handling hence in condition not at all conducive 10
Now what wish TO show by the above is that, II |
our ships are 10 be compared with foreign ones, the
comparisons should he fair loah-diaught Uial
should not be compared with hghtdrsnght one
six hours run should not Dc compared with squirt
over an eleven Fix miles course the power FRO
dnced by ordinary seamng coal should not be com
pared with that got IRON picked COAL suoh a. lhe
sircs 10 compare the speed OF the Atlanta with the
other vessels mentioned, let him import lew tons oil
tn. finest English and then send the Atlanta on
one squirt over the measured nile In smooth water
" ould also advise Mr.. Whitney TO be more careful
in making comparisons which msleAd people into
believing that our ships much inferior To those
built by other Deople. ! understand that In the
NAVY Department there IS I" Bureau ot Intelii-
pence the supposed functions OF which are TO collect
naval information from all the world. II the
Secretary hal referred his statements to the officers
OF that Bureau before publishing them believe they
could have shown him his mistakes; and, perhaps |
with their superior facilities, have pointed ont more
errors than am able 10 do with the limited means at
INV command A MARINE ENGINEER.
'k,, York Jan 26. 1887.